YouTube phenomenon is wonderful, perhaps like mp3 one.
and of course there other ones that better, but it does not matter, because now, as the result tons and tons of amazing things are accessible to people.

here list my most favorite 12 (used to be 20, but they got removed from youtube, that's why i recommend you to download and save you favorite ones too)

of course I have a lot more favorites at youtube.com/thedimkaand I prefer to aggregate things there instead of posting them in here or in LJ all the time